Population Ecology (2011) 53, 587-596

Jeffrey A. Harvey and Rieta Gols (2011)
Development of Mamestra brassicae and its solitary endoparasitoid Microplitis mediator on two populations of the invasive weed Bunias orientalis
Population Ecology 53 (4), 587-596
Abstract: The warty cabbage Bunias orientalis is an invasive pest in much of central Europe, including much of Germany since the 1980s, whereas in other countries, such as The Netherlands, it is a less common exotic species. Here, healthy larvae of Mamestra brassicae, which has been found feeding on B. orientalis plants in Germany, and larvae parasitized by one of its major larval endoparasitoids Microplitis mediator, were reared on both herbivore-induced and noninduced leaves of B. orientalis originating from single large populations growing in The Netherlands and central Germany. Herbivore performance was less negatively affected than parasitoid performance by differences in plant quality. Development times in both M. brassicae and Mi. mediator were shorter on Dutch than German plants and also shorter on noninduced than induced plants. Moreover, survival and body size of the parasitoid was more strongly affected by plant population and induction than survival of healthy M. brassicae. Chemical analyses of defensive secondary metabolites [glucosinolates (GS)] revealed that concentrations of the major GS sinalbin were constitutively expressed in German plants whereas they were induced in Dutch plants. However, in separate feeding bioassays in which preference for induced and noninduced leaves was compared separately, L3 instars of M. brassicae preferred noninduced German plants over Dutch plants but induced Dutch plants over German plants, revealing that changes in primary metabolites or an unidentified non-GS compound mediates population-related differences in plant quality. The results reveal asymmetric effects of plant quality in exotic plants on organisms in the second and third trophic level.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Jeffrey A. Harvey, Rieta Gols

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Mamestra brassicae		Germany
	Bunias orientalis (weed)		Germany
	Bunias orientalis (weed)		Netherlands
Microplitis mediator (parasitoid)	Mamestra brassicae		Netherlands